The onset and course of diabetic retinopathy are not readily predictable and there is considerable interindividual variability. Indicators of risk for the development of diabetic retinopathy in non-insulin-dependent diabetes mellitus will be studied in a clinic population of black women. Among Americans, black women appear to have an unusual disease experience due to excessive increases in diabetes rates, excess rates of obesity, and suspected excess of retinopathy. Data on the status of potential risk factors and on co-morbidity will be obtained from laboratory tests, medical records, and a patient interview on weight, while the status of the retina will be ascertained by direct and indirect ophthalmoscopy. The methodology emphasizes data definition and the use of standards and criteria recommended by national and international diabetes research groups for greater comparability of results. Groups with high and low retinal involvement will be identified from the retinal scores for four age classes. These groups will be tested for differences in the occurrence and levels of several indicators of risk. This process will include analysis of variance techniques and, alternatively, multiple regression techniques to identify risk factor interaction. The study examines the hypothesis that the rates of retinopathy are influenced by the distribution of risk factors. The findings could be useful in personal and institutional planning for preventive intervention in specific target groups, besides having conceivable implications for health policy formulation.